To be fair, casu marzu is really a Sardinian problem, but the buffalo dioxinarella comes home to roost in Italy proper, in the southern Campania region.

Quoth CNN:

Dioxin, a chemical environmental pollutant, can be hazardous even in small amounts. When it accumulates in the body, it can be linked to cancer, birth defects and organ failure.

Over the past week, Italian authorities have searched dozens of
buffalo dairies and seized milk samples for tests after
higher-than-permitted levels of dioxin were discovered in products from 29 mozzarella makers, news reports said.

Prosecutors in Naples have placed 109 people under investigation in connection with the probe, on suspicion of fraud and food poisoning, the ANSA news agency reported.

A garbage crisis may have something to do with the contaminated cheese, and finding the cause is not a trivial task: Buffalo mozzarella is a booming industry in Italy, with almost a half billion dollars of top-branded mozz sold each year in the country.